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1 | // Created on: 1993-03-24 |
2 | // Created by: DUB |
3 | // Copyright (c) 1993-1999 Matra Datavision |
4 | // Copyright (c) 1999-2014 OPEN CASCADE SAS |
5 | // |
6 | // This file is part of Open CASCADE Technology software library. |
7 | // |
8 | // This library is free software; you can redistribute it and/or modify it under |
9 | // the terms of the GNU Lesser General Public License version 2.1 as published |
10 | // by the Free Software Foundation, with special exception defined in the file |
11 | // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT |
12 | // distribution for complete text of the license and disclaimer of any warranty. |
13 | // |
14 | // Alternatively, this file may be used under the terms of Open CASCADE |
15 | // commercial license or contractual agreement. |
16 | |
17 | #ifndef _Geom2dConvert_BSplineCurveToBezierCurve_HeaderFile |
18 | #define _Geom2dConvert_BSplineCurveToBezierCurve_HeaderFile |
19 | |
20 | #include <Standard.hxx> |
21 | #include <Standard_DefineAlloc.hxx> |
22 | #include <Standard_Handle.hxx> |
23 | |
24 | #include <Standard_Real.hxx> |
25 | #include <Standard_Integer.hxx> |
26 | #include <TColGeom2d_Array1OfBezierCurve.hxx> |
27 | #include <TColStd_Array1OfReal.hxx> |
28 | class Geom2d_BSplineCurve; |
29 | class Standard_DimensionError; |
30 | class Standard_DomainError; |
31 | class Standard_OutOfRange; |
32 | class Geom2d_BezierCurve; |
33 | |
34 | |
35 | //! An algorithm to convert a BSpline curve into a series |
36 | //! of adjacent Bezier curves. |
37 | //! A BSplineCurveToBezierCurve object provides a framework for: |
38 | //! - defining the BSpline curve to be converted |
39 | //! - implementing the construction algorithm, and |
40 | //! - consulting the results. |
41 | //! References : |
42 | //! Generating the Bezier points of B-spline curves and surfaces |
43 | //! (Wolfgang Bohm) CAD volume 13 number 6 november 1981 |
44 | class Geom2dConvert_BSplineCurveToBezierCurve |
45 | { |
46 | public: |
47 | |
48 | DEFINE_STANDARD_ALLOC |
49 | |
50 | |
51 | //! Computes all the data needed to convert |
52 | //! - the BSpline curve BasisCurve, into a series of adjacent Bezier arcs. |
53 | //! The result consists of a series of BasisCurve arcs |
54 | //! limited by points corresponding to knot values of the curve. |
55 | //! Use the available interrogation functions to ascertain |
56 | //! the number of computed Bezier arcs, and then to |
57 | //! construct each individual Bezier curve (or all Bezier curves). |
58 | //! Note: ParametricTolerance is not used. |
59 | Standard_EXPORT Geom2dConvert_BSplineCurveToBezierCurve(const Handle(Geom2d_BSplineCurve)& BasisCurve); |
60 | |
61 | //! Computes all the data needed to convert |
62 | //! the portion of the BSpline curve BasisCurve |
63 | //! limited by the two parameter values U1 and U2 |
64 | //! for Example if there is a Knot Uk and |
65 | //! Uk < U < Uk + ParametricTolerance/2 the last curve |
66 | //! corresponds to the span [Uk-1, Uk] and not to [Uk, Uk+1] |
67 | //! The result consists of a series of BasisCurve arcs |
68 | //! limited by points corresponding to knot values of the curve. |
69 | //! Use the available interrogation functions to ascertain |
70 | //! the number of computed Bezier arcs, and then to |
71 | //! construct each individual Bezier curve (or all Bezier curves). |
72 | //! Note: ParametricTolerance is not used. |
73 | //! Raises DomainError if U1 or U2 are out of the parametric bounds of the basis |
74 | //! curve [FirstParameter, LastParameter]. The Tolerance criterion |
75 | //! is ParametricTolerance. |
76 | //! Raised if Abs (U2 - U1) <= ParametricTolerance. |
77 | Standard_EXPORT Geom2dConvert_BSplineCurveToBezierCurve(const Handle(Geom2d_BSplineCurve)& BasisCurve, const Standard_Real U1, const Standard_Real U2, const Standard_Real ParametricTolerance); |
78 | |
79 | //! Constructs and returns the Bezier curve of index |
80 | //! Index to the table of adjacent Bezier arcs |
81 | //! computed by this algorithm. |
82 | //! This Bezier curve has the same orientation as the |
83 | //! BSpline curve analyzed in this framework. |
84 | //! Exceptions |
85 | //! Standard_OutOfRange if Index is less than 1 or |
86 | //! greater than the number of adjacent Bezier arcs |
87 | //! computed by this algorithm. |
88 | Standard_EXPORT Handle(Geom2d_BezierCurve) Arc (const Standard_Integer Index); |
89 | |
90 | //! Constructs all the Bezier curves whose data is |
91 | //! computed by this algorithm and loads these curves |
92 | //! into the Curves table. |
93 | //! The Bezier curves have the same orientation as the |
94 | //! BSpline curve analyzed in this framework. |
95 | //! Exceptions |
96 | //! Standard_DimensionError if the Curves array was |
97 | //! not created with the following bounds: |
98 | //! - 1 , and |
99 | //! - the number of adjacent Bezier arcs computed by |
100 | //! this algorithm (as given by the function NbArcs). |
101 | Standard_EXPORT void Arcs (TColGeom2d_Array1OfBezierCurve& Curves); |
102 | |
103 | //! This methode returns the bspline's knots associated to |
104 | //! the converted arcs |
105 | //! Raises DimensionError if the length of Curves is not equal to |
106 | //! NbArcs + 1 |
107 | Standard_EXPORT void Knots (TColStd_Array1OfReal& TKnots) const; |
108 | |
109 | |
110 | //! Returns the number of BezierCurve arcs. |
111 | //! If at the creation time you have decomposed the basis curve |
112 | //! between the parametric values UFirst, ULast the number of |
113 | //! BezierCurve arcs depends on the number of knots included inside |
114 | //! the interval [UFirst, ULast]. |
115 | //! If you have decomposed the whole basis B-spline curve the number |
116 | //! of BezierCurve arcs NbArcs is equal to the number of knots less |
117 | //! one. |
118 | Standard_EXPORT Standard_Integer NbArcs() const; |
119 | |
120 | |
121 | |
122 | |
123 | protected: |
124 | |
125 | |
126 | |
127 | |
128 | |
129 | private: |
130 | |
131 | |
132 | |
133 | Handle(Geom2d_BSplineCurve) myCurve; |
134 | |
135 | |
136 | }; |
137 | |
138 | |
139 | |
140 | |
141 | |
142 | |
143 | |
144 | #endif // _Geom2dConvert_BSplineCurveToBezierCurve_HeaderFile |